JP2016212310A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device equipped with high waterproofness.SOLUTION: A display device 10 comprises: a circuit board 20; a plurality of light-emitting devices 70 mounted on the circuit board 20 and having an element board 40, a light-emitting chip mounted on the mount side of the element board 40, and sealing part 60 for sealing the light-emitting chip and provided on the element board 40; and a protective part 100 provided on the circuit board 20. The protective part 100 seals the circumference of a contact face 80 between the element board 40 of a light-emitting device 70 and the sealing part 60 of the light-emitting device 70. The protective part 100 seals the circumference of a contact face 80 between the element board 40 of a light-emitting device 70 and the sealing part 60 of the light-emitting device 70.EFFECT: The waterproofness of the display device can be improved. Furthermore, as the light-emitting device comes in a simple configuration, the display device can be fabricated at low cost.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a display device.

As a display device installed outdoors, there is known a display device in which a plurality of light emitting diodes (LEDs) are mounted in a matrix on a substrate (see Patent Document 1).
The LED used in such a display device includes a substrate, an LED chip mounted on the substrate, and a resin package surrounding the LED chip. The LED chip is made of an epoxy resin, a silicon resin, or the like, and is sealed with a sealing material that fills a space surrounded by the resin package.

  Since a display device installed outdoors is exposed to rainwater or the like, the LED sealing material used and the resin package are in close contact with each other in order to prevent intrusion of rainwater or the like. Furthermore, the electrodes exposed on the side and bottom surfaces of the LED are covered with silicon resin or the like.

JP 11-340515 A

In recent years, as the number of LEDs used in a display device has increased due to an increase in resolution of the display device, it is required to reduce the cost of light emitting devices such as LEDs.
Therefore, in order to reduce the cost of the light emitting device, when the light emitting device is composed of a light emitting chip, a flat substrate on which the light emitting chip is mounted, and a sealing portion, a flat contact surface between the substrate and the sealing portion is provided. Since it is exposed to the outside of the light emitting device, rainwater or the like easily enters the inside of the light emitting device through the space between the substrate and the sealing portion at the contact surface between the substrate and the sealing portion. When rainwater or the like enters the light emitting device, a short circuit of the wiring of the light emitting device occurs. Therefore, the waterproofness of the display device is lowered.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a display device having high waterproofness.
Another object of the present invention is to provide a low-cost display device.

  The display device of the present invention includes a circuit board, a light emitting chip mounted on the circuit board, mounted on the mounting surface of the element substrate, and a sealing portion provided on the element substrate and sealing the light emitting chip. A plurality of light emitting devices and a protection part provided on the circuit board are provided. The protection portion seals the periphery of the contact surface between the element substrate of the light emitting device and the sealing portion of the light emitting device.

  According to the present invention, the protective part seals the periphery of the contact surface between the element substrate and the sealing part, so that the intrusion of water from between the element substrate and the sealing part is suppressed, and the waterproof property of the display device Will improve. In addition, since the light emitting device includes the element substrate, the light emitting chip mounted on the mounting surface of the element substrate, and the sealing portion that seals the light emitting chip, the display device can be manufactured at low cost.

It is a front view which shows the display apparatus which concerns on Embodiment 1 of this invention. It is sectional drawing which looked at the display apparatus shown in FIG. 1 by the AA line. It is a side view of the light-emitting device which concerns on Embodiment 1 of this invention. It is a front view of the light-emitting device which concerns on Embodiment 1 of this invention. It is sectional drawing which looked at the light-emitting device shown in FIG. 4 by the BB line. It is a front view of the light-emitting device which concerns on Embodiment 2 of this invention. It is sectional drawing which looked at the light-emitting device shown in FIG. 6 by the CC line. It is a front view of the light-emitting device which concerns on Embodiment 3 of this invention. It is sectional drawing which looked at the light-emitting device shown in FIG. 8 by the DD line. It is a front view which shows the display apparatus which concerns on Embodiment 4 of this invention. It is sectional drawing which looked at the display apparatus shown in FIG. 10 by the EE line | wire. 3 is a front view illustrating a display device in which a louver is provided in the display device according to Embodiment 1. FIG. It is sectional drawing which looked at the display apparatus shown in FIG. 12 by the FF line. It is sectional drawing which shows the display apparatus which provided the groove part and the louver in the display apparatus which concerns on Embodiment 4 of this invention. It is a front view of the display apparatus which combined the display apparatus which concerns on Embodiment 1 of this invention.

  Hereinafter, display devices according to embodiments of the present invention will be described with reference to the drawings. For easy understanding, it is assumed that the display device 10 is outdoors and the front surface (display surface) of the display device 10 is installed perpendicular to the ground, and the direction parallel to the ground and the front surface of the display device 10 is assumed. Will be described as an X-axis direction, a direction perpendicular to the ground as a Y-axis direction, and a direction perpendicular to the X-axis direction and the Y-axis direction as a Z-axis direction. The same applies to other embodiments.

Embodiment 1 FIG.
With reference to FIGS. 1-5, the display apparatus 10 which concerns on Embodiment 1 of this invention is demonstrated.
As shown in FIGS. 1 and 2, the display device 10 includes a circuit board 20, a plurality of light emitting devices 70 mounted on the mounting surface 22 of the circuit board 20, and a protection unit 100. The display device 10 is installed on a stadium, a wall surface of a building, and the like.

  The circuit board 20 is made of an insulating resin material or the like. The circuit board 20 includes wiring (not shown) for supplying power to the light emitting device 70. The circuit board 20 is provided with a driving IC (IC: Integrated Circuit) (not shown) that drives the light emitting device 70 via the wiring of the circuit board 20.

  The light emitting devices 70 are arranged in a matrix on the mounting surface 22 of the circuit board 20. A surface disposed on the front side of the display device 10 is an upper surface 71, a surface perpendicular to the mounting surface 22 of the circuit board 20 is a side surface 72, and a surface facing the upper surface 71 is a lower surface (not shown).

As shown in FIGS. 3 to 5, the light-emitting device 70 includes three LED chips 50r, 50g, and 50b that emit red light, green light, and blue light, and elements that mount the LED chips 50r, 50g, and 50b, respectively. The board | substrate 40 and the sealing part 60 which seals LED chip 50r, 50g, 50b on the element substrate 40 are provided.
The three LED chips 50r, 50g, and 50b emit red light, green light, and blue light, respectively. The light emission intensities of the LED chips 50r, 50g, and 50b are independently adjusted by the power supplied from the driving IC of the circuit board 20 to the LED chips 50r, 50g, and 50b via the wiring of the circuit board 20, respectively. Thereby, light of an arbitrary color is emitted from the light emitting device 70 with an arbitrary intensity. As a result, a color image or the like is displayed on the display device 10 by the plurality of light emitting devices 70 as a whole.

The element substrate 40 is a flat plate and is made of an insulating resin material. The element substrate 40 has wirings 43r and 44r for supplying power to the LED chip 50r, wirings 43g and 44g for supplying power to the LED chip 50g, and wirings 43g and 44g for supplying power to the LED chip 50g, and a mounting surface 42 for mounting the LEDs 50r, 50g, and 50b. Wiring 43b and 44b for supplying power are provided. The wiring 43r and the wiring 44r are each electrically connected to the LED chip 50r by wire bonding. Similar to the wirings 43r and 44r, the wirings 43g and 44g are electrically connected to the LED chip 50g by wire bonding. Each of the wirings 43b and 44b is electrically connected to the LED chip 50b by wire bonding.
The LED chips 50r, 50g, and 50b are arranged at the center of the mounting surface 42 of the element substrate 40, and are arranged at equal intervals in parallel with each other in this order in the X-axis direction.

  In addition, the element substrate 40 extends from a surface 45 perpendicular to the mounting surface 42 of the element substrate 40 to a surface 46 facing the mounting surface 42, and is electrically connected to the wirings 43r, 44r, 43g, 44g, 43b, 44b, respectively. 6 electrodes 47 are provided. Each of the six electrodes 47 is electrically connected to the wiring of the circuit board 20.

  Therefore, power is supplied to the LED chip 50r from the driving IC of the circuit board 20 via the wiring of the circuit board 20, the electrode 47, the wirings 43r and 44r, and the bonding wires (not shown). Similarly to the LED chip 50r, the LED chips 50g and 50b are also supplied with power from the drive IC of the circuit board 20.

The sealing part 60 is comprised from translucent resin, such as an epoxy resin, a polyester resin, an acrylic resin, and a silicon resin.
The sealing part 60 has a rectangular parallelepiped shape. The sealing unit 60 is provided on the element substrate 40 and seals the LED chips 50 r, 50 g, and 50 b on the element substrate 40. The sealing portion 60 is in close contact with the mounting surface 42 of the element substrate 40 and the wirings 43r, 44r, 43g, 44g, 43b, 44b, and constitutes a contact surface 80 where the element substrate 40 and the sealing portion 60 come into contact.

The protection unit 100 is provided on the circuit board 20 and seals the periphery of the contact surface 80 between the element substrate 40 and the sealing unit 60.
In the present embodiment, the protection unit 100 is a film made of a resin having translucency and waterproof properties such as polyester resin, polycarbonate resin, acrylic resin, and silicon resin. The thickness of the protection part 100 is, for example, 50 to 300 μm. Moreover, the protection part 100 has an adhesion layer on one surface.
The protection unit 100 is in close contact with the mounting surface 22 of the circuit board 20 and the upper surface 71 and the side surface 72 of the light emitting device 70 along the mounting surface 22 of the circuit board 20 and the upper surface 71 and the side surface 72 of the light emitting device 70. The periphery of the contact surface 80 between the substrate 40 and the sealing portion 60 is sealed.

Next, a method for manufacturing the display device 10 having the above configuration will be described.
First, the light emitting device 70 is manufactured as follows.
An element substrate 40 including wirings 43r, 44r, 43g, 44g, 43b, 44b and an electrode 47 is prepared.
The LED chips 50r, 50g, and 50b are electrically connected to the wirings 43r, 44r, 43g, 44g, 43b, and 44b by wire bonding and mounted on the prepared element substrate 40.
The sealing part 60 is formed on the mounting surface 42 of the element substrate 40 on which the LED chips 50r, 50g, and 50b are mounted by molding. As a result, the sealing unit 60 seals the LED chips 50r, 50g, and 50b, and comes into close contact with the mounting surface 42 of the element substrate 40 and the wirings 43r, 44r, 43g, 44g, 43b, and 44b. Thus, the light emitting device 70 can be manufactured.
Next, the circuit board 20 provided with wiring is prepared.
Each light emitting device 70 is mounted on the prepared circuit board 20 by soldering the electrode 47 of the manufactured light emitting device 70 to the wiring of the circuit board 20 by a reflow method or the like.
The circuit board 20 and the protection unit 100 are installed in a vacuum vessel, and the inside of the vacuum vessel is deaerated and decompressed.
The mounting surface of the circuit board 20 is arranged so that the surface on which the adhesive layer of the protection unit 100 is provided is aligned with the upper surface 71 and the side surface 72 of the light emitting device 70 and the mounting surface 22 of the circuit board 20 in the decompressed vacuum container. Affix to 22.
The inside of the vacuum vessel is returned to normal pressure, and the circuit board 20 with the protection unit 100 attached is taken out of the vacuum vessel.
Since the protection unit 100 is affixed to the mounting surface 22 of the circuit board 20 in a decompressed vacuum container, when the circuit board 20 is taken out from the vacuum container, the protection unit 100 is pressed by the atmospheric pressure, and the upper surface of the light emitting device 70. 71, the side surface 72, and the mounting surface 22 of the circuit board 20 are in close contact, and the periphery of the contact surface 80 between the element substrate 40 and the sealing portion 60 is sealed.
As described above, the display device 10 can be manufactured.

As described above, since the protection unit 100 seals the periphery of the contact surface 80 between the element substrate 40 and the sealing unit 60, it prevents water from entering the light emitting device 70 and waterproofs the display device 10. Can be improved.
In addition, since the light emitting device 70 has a simple configuration including the LED chips 50r, 50g, and 50b, the element substrate 40 on which the LED chips 50r, 50g, and 50b are mounted, and the sealing portion 60, the display device 10 is low. Can be manufactured at low cost.

Embodiment 2. FIG.
In Embodiment 1, although the light-emitting device 70 whose shape of the sealing part 60 is a rectangular parallelepiped was used, the shape of the sealing part 60 is not restricted to a rectangular parallelepiped. In the following description, the surface of the sealing unit 60 disposed on the front side of the display device 10 is the upper surface 62 of the sealing unit 60, and the surface perpendicular to the mounting surface 22 of the circuit board 20 is the side surface 64 of the sealing unit 60. To do.

In the present embodiment, as shown in FIGS. 6 and 7, the upper surface 62, which is one of the boundary surfaces with which the sealing portion 60 contacts the external space, passes through the center point U of the mounting surface 42 of the element substrate 40. The inclination is away from the central axis 114 perpendicular to the substrate 40 and approaches the mounting surface 42 of the element substrate 40. For example, the upper surface 62 is a convex surface. The height (length in the Z-axis direction) H1 of the side surface 64 of the sealing portion 60 from the mounting surface 42 of the element substrate 40 is the upper end of the LED chips 50r, 50g, and 50b from the mounting surface 42 of the element substrate 40. (Height in the Z-axis direction) H2.
Further, the electrode 47 of the light emitting device 70 is provided on a surface 46 facing the mounting surface 42 of the element substrate 40 through a through hole 48 provided in the element substrate 40. Other configurations are the same as those in the first embodiment.

Since the upper surface 62 of the sealing portion 60 is inclined away from the central axis 114 passing through the center point U of the mounting surface 42 of the element substrate 40 and perpendicular to the element substrate 40 and approaching the mounting surface 42 of the element substrate 40, the film The protection unit 100 that follows easily follows the shape of the sealing unit 60, so that the protection unit 100 can be in close contact with the sealing unit 60. Moreover, peeling from the sealing part 60 of the protection part 100 can be suppressed. Furthermore, since the stress applied to the protection part 100 is dispersed, the deterioration of the protection part 100 can be suppressed. Therefore, the reliability of the display device 10 is further improved.
Moreover, the waterproofness of the display apparatus 10 can be improved similarly to the display apparatus 10 of Embodiment 1. Furthermore, the display device 10 can be manufactured at a low cost, similar to the display device 10 of the first embodiment.

Embodiment 3 FIG.
In Embodiment 2, although the upper surface 62 of the sealing part 60 in the light-emitting device 70 is a convex surface, the shape of the sealing part 60 is not limited to this.

In the present embodiment, as shown in FIGS. 8 and 9, the boundary surface 110 where the sealing portion 60 is in contact with the external space is composed of a plane 120 parallel to the mounting surface 42 of the element substrate 40 and a curved surface 122. Yes. Other configurations are the same as those of the second embodiment.
Hereinafter, the boundary surface 110 will be described in detail.

In the present embodiment, when the light emitting device 70 is viewed in plan from the direction of the boundary surface 110, the side farthest from the center point U parallel to the Y axis of the LED chip 50 r and the LED chip 50 b on the mounting surface 42 of the element substrate 40. When the light emitting device 70 is viewed in plan from the direction of the boundary surface 110, the region that overlaps the mounting region M of the boundary surface 110 is the plane 120.
A region from each side of the plane 120 of the boundary surface 110 to each side of the mounting surface 42 of the element substrate 40 is a curved surface 122, and the curved surface 122 is inclined away from the central axis 114 and approaching the mounting surface 42 of the element substrate 40. have. Further, the curved surface 122 is continuous with a surface 45 perpendicular to the mounting surface 42 of the element substrate 40.

Since the region from each side of the flat surface 120 of the boundary surface 110 to each side of the mounting surface 42 of the element substrate 40 is the curved surface 122, the protective unit 100 that is a film is formed of the sealing unit 60 as in the second embodiment. The protection part 100 can be closely attached to the sealing part 60 while following the shape easily. Moreover, peeling from the sealing part 60 of the protection part 100 can be suppressed. Since the stress applied to the protection unit 100 is dispersed, deterioration of the protection unit 100 can be suppressed. Further, since the curved surface 122 is continuous with the surface 45 perpendicular to the mounting surface 42 of the element substrate 40, the protection unit 100 has the shape of the sealing portion 60 even at the portion where the sealing portion 60 and the element substrate 40 are in contact with each other. It easily follows the shape of the element substrate 40. Therefore, the protection part 100 can be more closely attached to the sealing part 60 and the element substrate 40, and peeling of the protection part 100 can be suppressed. As a result, the reliability of the display device 10 is further improved.
Further, similarly to the display device 10 of the first embodiment, the waterproofness of the display device 10 can be improved, and the display device 10 can be manufactured at low cost.

Embodiment 4 FIG.
In the first and second embodiments, the periphery of the contact surface 80 between the element substrate 40 and the sealing portion 60 is sealed by the protective portion 100 that is a film, but the contact surface between the element substrate 40 and the sealing portion 60 is used. The member that seals the periphery of 80 is not limited to a film.
In the present embodiment, as shown in FIGS. 10 and 11, the protection unit 100 of the display device 11 is a coating member that fills the space between the light emitting device 70 and the light emitting device 70. Other configurations are the same as those of the first embodiment.

  The protection unit 100 is a coating member having translucency and waterproof properties such as polyester resin, polycarbonate resin, acrylic resin, and silicon resin. The protection unit 100 is provided on the circuit board 20 and fills the space between the light emitting device 70 and the light emitting device 70. The protection unit 100 is in close contact with the side surface 72 of the light emitting device 70. Further, the upper end of the protection unit 100 between the light emitting device 70 and the light emitting device 70 has a height from the mounting surface 22 of the circuit board 20 higher than the height of the contact surface 80 between the element substrate 40 and the sealing unit 60. Located in position.

  The protection unit 100 is formed by, for example, injecting a resin between the light emitting device 70 and the light emitting device 70 on the mounting surface 22 of the circuit board 20 by a dispenser, and then curing the resin. Alternatively, after the protective part 100 is molded in advance using a mold, the protective part 100 may be provided between the light emitting device 70 and the light emitting device 70 on the mounting surface 22 of the circuit board 20 and bonded to the light emitting device 70. .

Since the protection unit 100 can be formed by injecting and curing resin, or by providing the protection unit 100 prepared in advance on the mounting surface 22 of the circuit board 20, the display device 10 can be manufactured more easily.
Further, since the protection unit 100 is in close contact with the side surface 72 of the light emitting device 70 and the upper end of the protection unit 100 is positioned higher than the contact surface 80 between the element substrate 40 and the sealing unit 60, the protection unit 100 The periphery of the contact surface 80 between the substrate 40 and the sealing portion 60 can be sealed. Therefore, similarly to the display device 10 of the first embodiment, the waterproofness of the display device 11 can be improved. Further, the display device 11 can be manufactured at a low cost, similarly to the display device 10 of the first embodiment.

  As mentioned above, although several embodiment of this invention was described, this invention is not limited to said embodiment, A various change is possible in the range which does not deviate from the summary of this invention.

  For example, the light emitting device 70 is not limited to a device including three LED chips that emit red light, green light, and blue light. The emitted light from the light emitting device 70 may be monochromatic light. Further, in the matrix arrangement of the light emitting devices 70, the light emitting device 70 that emits red light, the light emitting device 70 that emits green light, and the light emitting device 70 that emits blue light may be repeatedly arranged in the column direction.

  The shape of the electrode 47 of the light emitting device 70 is arbitrary. For example, in order to be connected and fixed to the wiring of the circuit board 20, a BGA (Ball Grid Array) type electrode in which ball-shaped electrodes are arranged on the lower surface of the light emitting device 70 may be provided.

  Further, the side surface 72 of the light emitting device 70 may be provided with a side wall that reflects or scatters the light emitted from the LED chips 50r, 50g, and 50b. For example, a side wall that reflects or scatters the light emitted from the LED chips 50r, 50g, and 50b may be provided on a part of each of the side surfaces 72 of the light emitting device 70.

  The matrix arrangement of the light emitting devices 70 is not limited to the same pitch of each row (each column). For example, the matrix-like arrangement of the light emitting devices 70 may be an arrangement shifted by a half pitch for each row (one column).

In Embodiment 1, the protective unit 100 has an adhesive layer, but the protective unit 100 may have an adhesive function instead of the adhesive layer.
In the first embodiment, the periphery of the contact surface 80 between the element substrate 40 and the sealing portion 60 is sealed using a vacuum vessel. However, the method for sealing the periphery of the contact surface 80 is not limited thereto. I can't. For example, a film having a heat bonding function is used as the protection unit 100, and is closely attached to the mounting surface 22 of the circuit board 20 and the surface of the light emitting device 70 while heating, and the periphery of the contact surface 80 between the element substrate 40 and the sealing unit 60 is formed. It may be sealed.

  12 and 13, a louver 150 that blocks outside light may be provided between the light-emitting device 70 and the light-emitting device 70 of the display device 10 according to the first embodiment. For example, the louver 150 extends in the X-axis direction and absorbs external light. Since the louver 150 suppresses reflection of external light by the display device 12, the display contrast of the display device 12 can be improved. The louver 150 can also be provided in the display device 10 in the second embodiment and the display device 10 in the third embodiment.

  Furthermore, a groove portion 160 along the side surface 72 of the light emitting device 70 and the mounting surface 22 of the circuit board 20 may be provided in the protective portion 100 that is a coating member. Thereby, as shown in FIG. 14, a member such as the louver 150 can be provided in the groove 160 of the display device 13.

  By combining a plurality of display devices 10 to 13, a larger display device can be configured. As shown in FIG. 15, four display devices 10 are combined to form a display device 200. In addition, you may combine the display apparatuses 10-13 from which a structure differs.

10, 11, 12, 13, 200 Display device, 20 Circuit board, 22, 42 mounting surface, 40 Element substrate, 43r, 43g, 43b, 44r, 44g, 44b Wiring, 45 Surface perpendicular to mounting surface, 46 Mounting surface , 47 electrodes, 48 through-holes, 50r, 50g, 50b LED chip, 60 sealing portion, 70 light emitting device, 62, 71 upper surface, 64, 72 side surface, 80 contact surface, 100 protective portion, 110 boundary surface 114 center axis, 120 plane, 122 curved surface, 150 louver, 160 groove, U center point

Claims (7)

A circuit board;
A plurality of light emitting devices mounted on the circuit board and having an element substrate, a light emitting chip mounted on a mounting surface of the element substrate, and a sealing portion provided on the element substrate and sealing the light emitting chip;
A display device, comprising: a protection portion that is provided on the circuit board and seals a periphery of a contact surface between an element substrate of the light emitting device and a sealing portion of the light emitting device.   The sealing portion has a boundary surface of the sealing portion that is in contact with an external space, passes through a central point of the mounting surface of the element substrate, is separated from a central axis perpendicular to the element substrate, and approaches the mounting surface of the element substrate. The display device according to claim 1, wherein the display device has an inclination.   The display device according to claim 2, wherein a boundary surface of the sealing portion is a curved surface continuous with a surface perpendicular to a mounting surface of the element substrate.   The display device according to claim 1, wherein the protection unit is a film-like resin having flexibility.   The display device according to claim 1, wherein the protection unit is a resin that fills a space between the light emitting devices.   The display device according to claim 5, wherein the protection portion has a groove portion along a surface of the light emitting device and a mounting surface of the circuit board.   A display device comprising a combination of a plurality of display devices according to claim 1.

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